A plating apparatus continuously plates a surface of a substrate with metal and performs its supplementary process in one housing unit. The plating apparatus comprises a cassette stage for placing a substrate cassette thereon, a pre-treatment unit for pre-treating a surface of a substrate, and a plating unit for plating a surface of the substrate pre-treated in the pre-treatment unit. The plating apparatus further comprises a first substrate stage disposed between the cassette stage and the pre-treatment unit, a cleaning and drying unit disposed between the cassette stage and the first substrate stage, a first transfer device, and a second transfer device. The first transfer device transfers a substrate between the substrate cassette, the cleaning and drying unit, and the first substrate stage. The second transfer device transfers a substrate between the first substrate stage, the pre-treatment unit, and the plating unit.